In the related art, most refrigerators have a shelf configured as a single rectangular flat glass shelf or a flat plastic shelf, and the glass shelf is placed on ribs in a liner or is engaged with the ribs in the liner to be fixed via a fitted structure of the glass shelf itself and the liner. Since the shelves are fixedly placed in the upper, middle and lower positions in the cabinet, the height and position of the shelf may not be adjusted at will. For the refrigerator having a large (high and deep) volume, it is very inconvenient to place food on the uppermost shelf and to take food off the uppermost shelf.
There are a few brands of refrigerators in the market that have introduced the lifting shelf bracket to meet a user's needs for storing food and other articles at different heights. For example, in a patent whose number is 201510149798.0 and whose title is “shelf assembly and refrigerator”, a groove is provided in a side wall of the refrigerator, and a plurality of rotary knobs are provided in the groove to support the shelf. However, this design may not adapt to any height as needed, and the height to be adjusted can only be a distance between two rotary knobs. Similarly, in a patent whose number is 201120239738.5 and whose title is “refrigerator and device for raising and lowering shelves thereof”, a plurality of recesses that match support blocks on both sides of the shelf are provided in the refrigerator, and the shelf is fixed via engaging the support block in the recess. This design also has the disadvantage of not being able to adapt to any height as needed. Moreover, when adjusting the height of the shelf, it is necessary to manually hold the shelf, which is inconvenient for operation. For another instance, in a lifting shelf described in patent CN01112021.5, the shelf can be moved up and down as a whole by adjustment. This shelf has an advantage that the height of the shelf can be effectively adjusted, so as to save space for placing the lower objects, and hence the function of the shelf can be effectively utilized. However, this structure also has an insufficient lifting height, and when the shelf is provided with a heavy object thereon, there may be the risk of screw tripping.